28-spotted ladybird: identify, prevent, control

Active through the warm growing season, October to April, peaking in mid to late summer.

The 28-spotted ladybird is the rare plant-eating ladybird, unlike its helpful spotted cousins. Both adults and larvae graze the leaves of potatoes, tomatoes, beans and cucurbits, leaving a distinctive lacy skeleton of damage.

How to identify it

• Dome-shaped orange-brown beetle with 28 black spots, larger and duller than helpful ladybirds
• Lacy, skeletonised patches where leaf tissue is grazed between the veins
• Spiky yellowish larvae feeding on leaf undersides
• Damage concentrated on potatoes, tomatoes, beans and pumpkins

How to prevent it

• Learn to tell them from beneficial ladybirds, which are smaller, shinier and have fewer spots
• Remove old solanum weeds like blackberry nightshade that host them
• Cover vulnerable crops with fine netting in peak season
• Clear up spent cucurbit and potato plants where they overwinter

Organic control, step by step

• Hand-pick adults and larvae and squash the yellow egg clusters on leaf undersides
• Spray eco-neem to deter feeding on heavily attacked plants, repeating weekly
• Use pyrethrum at dusk for a knockdown when numbers are high
• Check leaf undersides regularly through the growing season to stay ahead of breeding
• Remove the worst-affected leaves to slow the population

Plants it attacks